Monocarboxylic acid diesters of 1, 1&#39;-dialpha-hydroxy methyl ferrocene



United States Patent C) 3,217,019 MONOCARBOXYLIC ACID DIESTERS F 1,1'-DI- ALPHA-'HYDROXY METHYL FERROCENE Edwin L. De Young, Milwaukee, Wis., assignor to Standard Oil Company, Chicago, Ill., a corporation of Indiana No Drawing. Filed May 22, 1961, Ser. No. 111,437

2 Claims. (Cl. 260-410.6)

This invention relates to monocarboxylic acid diesters of 1,1'-di-alpha-hydroxy methyl ferrocene. The esters are useful as addition agents for oleaginous compositions such as hydraulic fluids, synthetic oils, greases, fuels and lubricating oils especially for use in lubricating alloy hearings in heavy duty diesel engines.

The compounds of this invention are the C to C monocarboxylic acid diesters of 1,l'-di-a.lpha-hydroxy methyl ferrocene.

Examples of compounds of this invention are the aromatic, open chain aliphatic and cyclo aliphatic monocarboxylic acid diesters of 1,l'-di-alpha-hydroxy methyl ferrocene. More specifically, the l,l'-di-alpha-hydroxy methyl ferrocene diesters of the following carboxylic acids are intended within the scope of the present discovery: formic acid, acetic acid, propionic acid, butyric acid, caprylic acid, caproic acid, capric acid, myristic acid, stearic acid, oleic acid, linoleic acid, docosanoic acid, palrnitic acid, naphthenic acid, naphthalenic acid, anthracenic acid, benzoic acid, nonyl benzoic acid, phenyl acetic acid, S-phenyl caprylic acid, 5-laurylnaphthalenic acid, hexahydrobenzoic acid, abietic acid, linolenic acid, dodecadienic acid, valeric acid, crotonic acid, acrylic acid, vinyl acetic acid, 4-phenyl crotonic acid, cyclopropane-carboxylic acid, cyclopentane-carboxylic acid, cyclopentene-carboxylic acid, tetrahydrobenzoic acid, cyclo-octane-carboxylic acid, cyclobtuane-carboxylic acid, cyclo-octatetraenecarboxylic acid, cyclo-heptane-carboxylic acid, as well as the alkylated derivatives and homologues of the above.

The compounds of this invention are believed to correspond to the following structural formula:

wherein R is the hydrocarbon group derived from the carboxylic acid, i.e. contains from 1 to 22 carbon atoms as defined above.

The diesters of this invention are prepared by reacting one mole of l,1'-di-alpha-hydroxy methyl ferrocene with 2 moles of corresponding monocarboxylic acid. Advantageously, a hydrogen chloride acceptor, e.g. an amine such as dimethyl aniline, may be included in the reaction mixture to tie up free hydrogen chloride. The reaction is that of an acid chloride with an alcohol and is well known to the art. The conditions for the reaction are also well known to the art, although it is preferred to carry out the reaction at a temperature above about 100 F., e.g. in the range of IOU-300 F.

As a typical preparation of a carboxylic acid diester of 1,1'-di-alpha-hydroxy methyl ferrocene, to a solution of 1,1'-di-alpha-hydroxy methyl ferrocene in hexane containing dimethyl aniline as a hydrogen chloride acceptor, 2 moles of caprylyl chloride were added dropwise. The

3,217,019 Patented Nov. 9, 1965 reaction mixture was stirred under reflux conditions for four hours and then cooled and filtered from the dimethyl aniline hydrochloride. The hexane solution was then concentrated to give a product which had an iron content of 3.64%, the dicaprylyl diester of l,l-di-al-pha-hydroxy methyl ferrocene. This particular product is especially preferred for use as a wear inhibitor in lubricating oils used for the lubricating of silver alloy hearings in heavy duty diesel engines.

A particular advantage of the compounds of this invention flows from the ability to inhibit wear of silver bearings, e.g. those used in heavy duty diesel engines, under conditions of bearing operation while still retaining good oxidation stability of the lubricating oils. Many silver alloy bearing wear inhibitors also function to reduce the oxidation stability of the lubricating oil and permit the formation of acids from the deterioration of the lubricating oil, which acid, particularly in the presence of water, are corrosive toward ferrous metal parts with which they come into contact. The compositions of this invention improve the oxidation stability and also impart rust inhibition and protection of ferrous metal parts.

The compounds of this invention may also be added to internal combustion engine fuels or lubricants to improve octan requirement increase (ORI) and to suppress the formation of combustion chamber deposits. The compounds are also useful in oleaginous bases (base oils) generally as rust inhibitors and, where necessary, as oxidation stabilizers. For use as rust inhibitors in base oils, it is preferred that the diesters be the non-cyclic (open chain) hydrocarbon monocarboxylic acid diesters having a straight chain containing from 6 to 22 carbon atoms. However, it is to be understood that all compounds herein disclosed may be advantageously used in base oi-ls as rust inhibitors.

The oleaginous bases, i.e. oleaginous vehicles, useable in compositions with the compounds of this invention are well known in the art. Such base oils include oils used for lubricating purposes, as fuels, as cutting oils, as slushing compound vehicles, as grease bases, as metal-working oils, as insecticide carriers, as mold lubricants, etc. More specifically, such oils include the lubricating oils such as the mineral lubricating oils as well as both other hydrocarbon oils, both natural and synthetic, for example, those obtained by polymerization of olefins. The base oil may be a synthetic oil of the alkylene oxide type and the monoand poly-carboxylic acid ester type, e.g. the oil-soluble esters of adipic acid, sebacic acid, azelaic acid, etc. The lubricating oils may be the light oils used as break-in oils in internal combustion engines or heavier oils used for normal lubricating of internal combustion engines, also contemplated are the heavier lubricating oils used in lubrication of differentials and other gear boxes as well as industrial machinery. The lubricating oils may con tain other addition agents, e.g. thickening agents in an amount sufficient to thicken them to grease consistency.

Additionally, the addition agents are useful in light and heavy oils normally used as fuels. The fuels may be distillate fuels or residual or blends thereof as well as blends of distillate and residual fuels alone. The fuels may be gasoline, leaded or unleaded, as well as diesel fuels, heater oils, furnace oils and other oils used in burner installations, virgin gas oil, light catalytic cycle oils, medium and heavy catalytic cycle oils, heavy industrial fuels (e.g. bunker C), heater oil fractions, jet fuels, kerosene, gas oil, etc.

Slushing compositions containing the addition agents disclosed herein as rust inhibitors are also contemplated. Such slushing oils conventionally use oleaginous bases as carriers for the rust inhibiting compound. The oleaginous base is preferably a liquid solvent for the rust inhibitor. Such base oils include many of the oils mentioned above, as well as crude oil, xylene, benzene, low melting hydrocarbon waxes, alcohols, thickened lubricating oils, hydrocarbon oils generally, etc. Also contemplated are metal working oils such as the light lubricating oils, e.g., SAE 5 through SAE 20, and the light metal cutting oils which may include oils such as white oils, kerosene, low molecular weight ester oils and the like.

The slushing compositions as defined above are useful in the general uses for slushing compounds, i.e. the coating of ferrous metal surfaces to protect against rusting and corrosion. In such application, such surfaces as tank walls, concrete forms, structural ferrous members and walls, and the like, may be advantageously protected against rusting by using slushing compounds disclosed herein. When using compounds of this invention in slushing oils, it is advantageous to include them in amounts of from about 0.01 to about 25 weight percent (although 0.5 weight percent is usually sufficient).

In use in lubricating oils, it may be advantageous to use from about 0.0001 to or more depending upon the severity of conditions to which the lubricating oil is exposed. Amounts in excess of 10% may be used where desirable or necessary. When the compositions of this invention are used as rust inhibitors in engine lubricating oils, it is preferred to use from about 0.001 to about 1 weight percent. For other uses, amounts may be employed as necessary or desirable. The compositions of this invention may also be compounded in concentrates in a base oil or other solvent for any of the above uses, e.g. as concentrates containing from to 70% of the rust inhibitor compound. The amounts given hereinabove are given as suggested guides to those skilled in the art and are not limiting on the present invention.

In the preferred use of the compounds as silver wear and oxidation inhibitors in diesel lubricating oils, 0.01 to 1% is usually sufficient although amounts up to 5% or more may advantageously be employed.

In order to further show the utility of the compounds of this invention, a blended mineral lubricating oil having a viscosity of 80 Saybolt Seconds at 210 F., containing 2.8% of a neutralized phosphorus sulfide-hydrocarbon reaction product as a detergent, 0.2% of sulfurized terpene and 1.0% of calcium phenol sulfide as an oxidation inhibitor, was used as a base oil and 0.2% of the dicaprylyl diester of 1,1-di-alpha-hydroxy methyl ferrocene was added thereto and tested in accordance with the silver Falex Wear test. For comparison purposes, the same base oil without the compound of this invention was also tested in accordance with the same procedure. In accordance with the Falex test, the compositions were tested in Falex testing machine using a silver bearing. Briefly, the machine consists of two plates having opposing grooves with a silver bearing in the grooves and positioned between the plates. Pressure is exerted against the bearing from both plates while the bearing is rotated. After a given period of time, the bearing is removed and weighed and the weight is compared to the weight of the bearing before the test. The difference in weight, i.e. weight lost due to wear, is reported below for each sample.

The data of the above table demonstrates the ability of the present addition agents to inhibit wear of silver alloy bearings, the preferred use for compounds of this invention.

The dicaprylyl of diester 1,1-di-alpha-hydroxy methyl ferrocene was also tested for rust inhibiting properties in the ASTM D-665 Rust Test. Accordingly, the compound was included in a lubricating oil base and tested for rust preventing characteristics of the oil containing the additive in the presence of water. The test procedure is described in the 1949 Book of ASTM Standards, Part 5, pages 967- 971. The concentration of the additive used in the oil and the results of the test were as follows:

Concentration of additive, percent: Test results 0.1 Perfect rust inhibition 0.01 Perfect rust inhibition The rust test carried out abov not only demonstrates the ability of the compounds of this invention to impart rust inhibiting properties to a lubricating oil but also demonstrates that the compounds of this invention do not adversely affect the oxidative stability of the oil and actually act as oxidation inhibitors. The compositions of this invention suppress oxidation of the oil and resulting rusting of ferrous metals.

It is evident from the foregoing that I have provided new and useful diesters of 1,1'-di-alpha-hydroxy methyl ferrocene and rust inhibited oleaginous compositions containing the same. As a particular contribution, I have provided compositions which are useable as silver alloy bearing wear inhibitors which do not adversely affect and, in fact, improve the oxidation stability of lubricating oils.

I claim:

1. The aliphatic non-cyclic straight chain hydrocarbon monocarboxylic acid diester of 1,1'-di-alpha-hydroxy methyl ferrocene wherein said straight chain has 6 to 22 carbon atoms.

2. The dicaprylyl diester of 1,1'-di-alpha-hydroxy methyl ferrocene.

References Cited by the Examiner UNITED STATES PATENTS 2,763,613 9/56 Scott et al 25232.5 2,763,617 9/56 Scott et a1 25249.7 2,810,737 10/57 Haven 260-439 2,875,223 2/59 Pedersen et al. 260-439 2,947,769 8/60 Pruett 260-439 CHARLES B. PARKER, Primary Examiner. JULIUS GREENWALD, Examiner. 

1. THE ALIPHATIC NON-CYCLIC STRAIGHT CHAIN HYDROCARBON MONOCARBOXYLIC ACID DIESTER OF 1,1''-DI-ALPHA-HYDROXY METHYL FERROCENE WHEREIN SAID STRAIGHT CHAIN HAS 6 TO 22 CARBON ATOMS. 